diff --git a/tests/graphics/bmpbundle.cpp b/tests/graphics/bmpbundle.cpp
index 0cacb8f3f0..6154c071d2 100644
--- a/tests/graphics/bmpbundle.cpp
+++ b/tests/graphics/bmpbundle.cpp
@@ -395,7 +395,9 @@ TEST_CASE("BitmapBundle::FromSVG-alpha", "[bmpbundle][svg][alpha]")
     // premultiplied storage in wxBitmap) to substantially original straight
     // alpha pixel values in wxImage, allowing for roundoff error.
     CHECK( (int)img.GetRed(0, 1) >= 0x3c );
+    CHECK( (int)img.GetRed(0, 1) <= 0x3f );
     CHECK( (int)img.GetGreen(0, 1) >= 0x7c );
+    CHECK( (int)img.GetGreen(0, 1) <= 0x7f);
     CHECK( (int)img.GetBlue(0, 1) == 0xff );
 }